The process of recording and playing video tapes results in the generation of a considerable amount of abrasive debris or wear products causing deterioration of tape performance. During record, play and wind modes, this debris is deposited on both sides of the video tape.
These wear products consist of small pieces of coating and base film removed from the tape by normal abrasion. These particles collect on any fixed surface, such as heads or guides, and slowly accumulate to form a projecting lump. Subsequently, surface temperature, created by friction from the moving tape, causes the debris to reattach to the tape surface.
It is the redisposition of this debris onto the tape surface that causes deterioration, accelerated head wear, tape drag and, finally, ultimate failure of the tape.
The tape cleaning and conditioning capabilities of the tape cleaner and degausser apparatus of the present invention constitute an important contribution towards overall improvement in video tape performance.
Regular use of the tape cleaner and degausser apparatus increases head and tape life. Additionally, the apparatus offers the benefits of precision rewinding and demagnetization of the video tape.
As the magnetic oxide crystals on magnetic tape continue to grow smaller, and the amount of information stored on the tape grows larger, it becomes more demanding that the surface of the tape be as clean as possible to prevent losing information because of poor tape to head contact.
The manufacture of video magnetic tape is a tedious and exacting process of growing magnetic oxide crystals and applying them to a sheet of base material such as acetate or Mylar polyester film in a plastic vehicle form of coating material and thereafter cutting the tape to the desired length and width. This is disclosed in U.S. Pat. No. 3,587,128.
The prior art describes several cleaning methods and apparatus such as U.S. Pat. No. 3,035,295, in which a metal or hard monocrystalline material scrapper with a uniform cutting edge is used to remove tape oxide from the tape.
Other tape cleaning apparatus are those pieces of apparatus described in the following U.S. Pat. Nos.:
3,266,196 describes a tape cleaner employing a gear reducer for driving the tape cleaning head;
3,475,782 describes a magnetic tape cleaner in which slight distortion of the tape is effected by two rollers on either side of a cleaning head and a hard monocrystalline material scrapper blade is used for scrapping the front surface of the tape;
3,701,178 describes a cassette tape cleaner with a plurality of scrapping blades that project into standard openings in the cassette when the cassette is inserted in the apparatus. A blast of air is then used to remove scrappings away from the blades and tape;
3,757,374 describes a magnetic tape cleaner where the tape contacts a blade having a plurality of cutting edges and then winds onto a take-up reel.
Other methods of cleaning magnetic tape have included the use of a solution in conjunction with ultrasonic agitation and, as disclosed in U.S. Pat. No. 4,620,256, a magnetic tape cleaner employing both scrapping and wiper means.
From the foregoing, it can been seen that the prior art has provided a variety of means of cleaning magnetic tape to avoid tape scratching, to remove metallic particles and other undesirable debris and to prevent unwanted loss of information from faulty tape to head contact.
Yet the prior art has not been totally satisfactory, probably because the embedded debris and other tape buildup was not adequately removed.
Additionally, one of the prior art discloses an apparatus capable of degaussing the tape at the same time the cleaning activity is taking place, or specifically designed to clean video magnetic tape in either a VHS or Beta format, as is the present invention.
None of the prior art has the easy access capability of the present invention allowing the replacement of the cleaning elements as needed.
Finally, the prior art does not reveal a bar condition station that allows a user to know when the cleaning bar needs to be rotated or changed.